It provides a lot of useful information including:

• host address
• network mask
• wildcard mask
• broadcast address
• first host in network>
• last host in network

Check it out here: Click To Use The Ip Subnet Calculator

Presently, the most common cloud computing services offered to businesses and consumers are remote backup services, project management services, video collaborative services, and online software applications including contact/lead management applications and accounting applications.

Microsoft cloud computing services are in the process of evolution as are Google cloud computing services. These services will be used by as many as eighty percent of all Fortune 1000 companies by the year 2012. More and more businesses are illustrating a serious interest in this technology as the technology begins to improve.

Cloud computing services are currently very affordable and business owners have come to appreciate that they do not have to invest in an expensive infrastructure in order to access the benefits provided by cloud computing services. The service providers provide the infrastructure. Typically cloud computing services are offered on a pay as you go basis and consumers can pay on a monthly basis. Another advantage is that remote access to business information can make business management easier if used well.
Many business owners are still concerned about the cons associated with cloud computing services. For one thing, they are concerned about sharing highly sensitive material in a virtual cloud environment that other businesses are using at the same time! Businesses are also concerned about interruptions in Internet service which can result in business downtime and loss of money. in order for cloud computing to really take off  business owners must develop a certain level of trust with the service provider. The best way to do this is with a contract! Any contract should include backups, security measures, service and uptime guarantees.

As time moves on, the providers of cloud computing services are beginning to make efforts to address the above mentioned concerns and to perfect their offerings. So eventually many more businesses will be using these services.

The Google Cloud is powered by thousands, perhaps millions of unique servers and services which house unbelievable amounts of information. These are located in different locations in the world and maintain a number of copies of the information that is accessible on the Internet. The information stored on the latter servers is what makes cloud computing such a powerful possibility when it comes to information access and management.

Google Cloud is basically a “reference” to the information that Google stores and makes accessible. Cloud computing services are the services that can be used from any location to access the information that Google saves. Services like Google Maps, Search, Blofs, Docs and so on. Google’s heavy duty servers are much like the hub of an amazing system of information – and cloud computer services are the means for accessing any and all information located within the hub of the information system.

Here is a Google Apps Coud Computing Talk On Video. He looks like he is asleep

Google is, of course, not the only company involved in cloud computing and in making efforts to offer cloud computing services. Amazon, Yahoo, and Microsoft cloud computing services are also in development stages. Cloud computing
services are expected to benefit scientists, researchers, corporations, and small business owners alike. Once cloud computing services become super easy to manage and navigate the services will become something accessible to the
masses.
Cloud computing services are relied on by a number of distinct entities looking to gain the advantages to be had from cloud computing. Cloud computing is seen as a method for business improvement by many and the demand for cloud
computing services has risen in the past few years, and because of its practicality the demand for such services will continue to rise.
Cloud computing services are offered by a variety of different companies. Features of such service include the ability to utilize specific software applications without the need for download or installation: such applications are supplied via a centralized service on the Internet instead. Online tools with complete instructions are also part of many cloud computing offerings. One will find that the use of cloud computing services is not only nicely affordable, but is
also relatively easy too since full instructions, guidance and support often comes with such services.
Despite all the conveniences that cloud computing services have to offer, some consumers remain leery about such services, citing privacy concerns as a source for their leeriness. Some consumers worry about the security of their files when they are stored on the Internet, and other consumers are concerned that traces of files will remain even after deletion. Other consumers are worried that their files might be analyzed so that they can be targeted for specific advertising, and still others are worried that their private information will be stored, assessed,
shared, and sold to third parties. Consumers seeking cloud computing services should take the time to carefully review any offer before signing up for any services. An offer should clearly define what information is stored, how it is
stored, how it is accessed and the rights of the consumer.

Cloud computers differ greatly from one’s desktop computer. A desktop
computer has a variety of hardware and software which are used either
separately or combined in order to help the computer user process information or
to help in entertaining the personal computer user. A personal computer is often
quite pricey due to all of the software and hardware which is included in the
device. Cloud computing takes information that would normally be stored on a
personal computer and brings the data into a virtual setting where it can be
readily accessed with greater ease and with a reliance on less equipment.

Cloud computing service is offered to computer users which allow the computer
user the ability to access his or her computer from a remote location. Files can
be accessed and shared with ease and the PC can be operated from anywhere
the PC user can get Internet access. Cloud computing services are presented to
consumers on a monthly, pay as you go basis. Cloud computing services are
also offered at prices which are tremendously affordable; costing about as much
as it costs for monthly Internet access. Furthermore, there is even free cloud
computing services available.

The notion of cloud computing is not at all new, the idea of using cloud
computing services has been floating around since 2000, and Google Cloud and
Microsoft Cloud computing are certainly services that consumers will be hearing
about more in the future as they continue to grow and evolve. Since all
information is stored and made accessible via a virtual environment, the limited
equipment needed to access information via cloud computing equipment is ultralightweight
and super user friendly too.

One of the primary concerns people maintain when it comes to using cloud
computing services today however, is the notion that the security of information is
a bit questionable. Consumers are concerned that their privacy may not be 100
percent protected, and many consumers are also concerned about where all the
information is stored once it is sent into the Internet cloud. There are also some
individuals that worry about what happens to one’s stored information if
payments are missed on cloud computing services. Clearly, many questions
need to be addressed before cloud computing becomes a way of information
management for the masses.

Hers is a quick 60 second video on Amazon EC2 cloud computing:

With DNS it is possible to allow multiple IP addresses to be associated with a single server name or hostname. So you might have 10 servers at the backend and one server at the front. The IP address of the frontend server is associated with the IP addresses of the backend servers.

When a request is made to the frontend server it load balances the requests across the backend servers in a round robin or one at a time basis.

This is easy to set up and configure however it’s simplicity is also its achilles heel. Namely:

* you can only use a round robin approach and not other more sophisticated approaches like least connections

* it cannot monitor servers to see if they are still up and running

* all requests are on a round robin basis do sticky sessions are not supported

* it is not possible to ensure an even load distribution across all of the backend servers

Nonetheless it is a simple approach that is easy to set up.

Here is a slightly oddball (but good) video that outlines the basics of DNS:

And here is a link to the wikipaedia explantion: http://en.wikipedia.org/wiki/Round_robin_DNS

With the growth of the Cisco IOS beyond what these could handle combined with the swell of the packet load of most networks these older routers can no-longer cut the mustard. Saying that, the Cisco 3600 series is still the router of choice for some people as they can be picked up very cheaply in the secondhand marketplace.

There is a Cisco ISR to suit everyone’s needs; from the 800 series for the small to medium-sized network right through large campus or high performance large network. These are more than just routers they now provide services like IPSec, VPN, firewalls, and VoIP.

Home office or small office

For constant VPN connections of up-to 10 home workers with good performance and reliability then look no further than the Cisco 800 Series. They have the Cisco IOS including IPS, VPN, VLAN, QoS, NAC, and Firewall. There are many routers in the range including wireless options and ISDN and DSL applications.

Small Remote Office

For networks that have up-to 25 or so users, the Cisco 1800 Series routers are the best choice. This router is ideal if all you need is a router to connect your office to the Internet, VPN, firewall, and wireless.

Larger Remote Office

If you require more performance and up scaling that the Cisco 1800 Series can offer, then you should look to the Cisco 2800 Series. Ideal for up-to around 50 users for office Internet connectivity, robust VPN access, with redundant power supply, Gig-E ports, NM expansion slots and Call Manager Express. Having the NM card slot lets you add things such as a 36-port switch with PoE, a DS3 ATM, a 24-port VoIP module, an intrusion detection module, a network analysis module, or a Cisco Unity Express voice mail module. Wonderful!

Office of 100 Workers or More

Cisco 3800 Series routers are similar to the 2800 Series in that there are a lot of HWIC and NM options for them. But what sets them apart from the 2800 Series is the sheer performance of the hardware and the number of HWIC and NM card that you can put into them.

Large HQ Office or Campus

For very large campus or service providers, the Catalyst 6500 and 7200/7300 Series platforms are for you. Cisco calls these “service aggregation platforms.” These are very high-performance networking platforms with a huge capacity for expansion.

About the Author

Matt Smith has been technical advisor to several Telecommunication companies such as Chess Telecom, Gemini Telecom & NB Data. Cisco Routers Selection

The key function of an internet time server or service is to provide accurate time to other computers on the internet. The time serving computer allows other computers to synchronise their clocks using a time signal that is carried across the internet. One example of an internet time service is NIST Internet Time Service which allows the synchronisation of computer clocks via the internet. Time servers read the current time from a reference clock and provides this information to all of the computers that use the service.

Network Time Protocol (npt) is the most commonly used protocol for synchronising time between multiple computers on a network. The actual time reference source is an atomic clock or GPS master clock.

Time servers are classified as being in a stratum on a scale fro 0 up to 14. The stratum refers to a hierarchy of time servers so the most accurate server will be on stratum 0, the next most accurate will be on stratum 1 and so on. The stratum 0 server will be highly specilaised uin order to provide as accurate as possible a time.

What is a Stratum 0 Time Server or Clock?

NTP uses a hierarchical client/server model. Each level in the hierarchy is called a stratum. At the top we have the stratum 0. This is the ultimate time reference and uses dedicated hardware devices to provide accurate time. Typically the “clock” at this stratum will be an atomic clock or a GPS satellite time signal.

What is a Stratum 1 Time Server?

At the next level in the hierarchy there are stratum 1 servers which provide time across the internet. These are clients of the stratum 0 servers. Hence the client/server model. These servers provide time across the internet and provide the most accurate timekeeping available on the internet.

What Is A Stratum?

From the above two explanations we can see that a stratum is the distance between two levels of time keeping or teo levels of accuracy. Hence the number of stratums is the distance that a particular time server is from a primary time keeping source. Stratums go from 0 to 16.

So we can see that ntp servers can reside in different stratas of the hierarchy.

Servers that are operating within the same starta can communicate with each other on a peer to peer basis (ie, we are all on the same level) and agree “who” has the most accurate time and they can then all synchronise to the most accurate time.

Another way that ntp time servers can communicate is via a broadcast (multicast) mechanism. In this case one server will broadcast a time signal and the client servers will all synchronise to that signal.

What Port does NTP Use?

Network services on a server are allocated “ports.” These are simply the address on the server where the required service is running. All major network services run on a defualt port so that it is easy to configure client computers to access the default port.

The network time protocol (ntp) uses UDP port 123 as its default port. This means that the service is available or accessable via port 123. The client computer will need to make its time synchronisation requests by connecting to this port on the ntp time server.

This type of load balancing uses part of the DNS functionality that allows more than one IP address to be associated with a single hostname (or server name). n order to load balance with DNS a round robin approach is used where the requests are routed to each backend server in turn. Strictly speaking it is not server load balancing but the DNS system itself runs on servers

The main benefit of this approach is that it is easy to set up and configure. However it is a simple process so there are a number of disadvantages of this approach which include:

• only round robin can be used
• DNS cannot detect if a server breaks down and is not operational
• sticky (same server) connections are not possible
• lod distribution can be unpredictable

So NAT allows a single device, such as a router or server, to act as an agent between a public network such as the internet and a private network. The owners of the private network usually will not want to expose all the IP addresses of the internal servers to the public so what happens is that one address is exposed to the public and this one address is then mapped onto multiple internal servers who can handle the public requests. This in turn means that only a single unique IP address is required to represent multiple servers.

A example is where a website has one IP address but web page requests are load balanced across multiple web servers who respond to the web page requests. Each of the web servers will have their own IP address but these private addresses will not be visible to the browsers making the web page requests. The browser only sees the one public IP address. This gives the browser the impression that there is only one computer or server handling the request but in reality there can be tens or even hundreds of web servers handling the page requests.